The applicant's successful LoJack® system includes a vehicle locating unit with a receiver and a transponder installed in a hidden location within a customer's vehicle. When the customer reports to the police that the vehicle has been stolen, that information is forwarded to a LoJack® control center whose databases ascertain that the vehicle includes a vehicle locating unit. The control center forwards a signal via a proprietary VHF tower network which is received by the receiver of the vehicle locating unit in the customer's vehicle. Upon receipt of this signal, the vehicle locating unit transponder is activated and its signal can be detected by a vehicle tracking unit installed in a police vehicle so that the police can thus track and locate the stolen vehicle. See U.S. Pat. Nos. 4,177,466 and 4,818,998 incorporated herein by this reference.
Since the advent of the LoJack® system, certain modifications and enhancements thereto have been invented. U.S. Pat. No. 5,917,423, for example, details ways to manually activate a vehicle locating unit transponder and also includes an automatic activation feature for the vehicle locating unit transponder when tampering with the vehicle is detected. U.S. patent application Ser. No. 10/150,818 discloses the use of a cellular network which can be used as an alternate communication channel to activate the vehicle locating unit transponder. See also U.S. Pat. Nos. 5,895,436; 6,229,988; 6,522,698; 6,665,613; 6,876,858; 6,847,825; and 7,091,835 all incorporated herein by this reference. See also co-pending application Ser. Nos. 10/241,259; 10/441,569; 10/886,870; 11/131,847; 11/131,948; 11/131,846; 11/229,736; 11/207,033; 11/502,191; 11/509,287; and 11/716,793, also incorporated herein by this reference.
Other vehicle recovery systems are also known. For example, UNI Tracking VTU Industries, Inc. offers a vehicle tracking unit with a GPS subsystem. Vehicle position data is forwarded to the customer's computer via a cellular network. One problem with systems that rely entirely on the Global Positioning System for tracking is that Global Positioning System signals are not available indoors or in so-called urban canyons. Still other vehicle tracking or locating systems determine the vehicle's location by cell tower triangulation techniques. One problem with such systems is the need for an expensive cell phone account. Hybrid systems are also available or have been proposed. Most of these systems suffer from the problems noted above and/or are expensive, complex, or unreliable. Moreover, non-LoJack® systems do not directly involve police intervention for theft reporting and tracking.
It has also been proposed to use RFID technology to track vehicles and objects. One problem with RFID technology is that it is fairly expensive to deploy. Numerous dedicated readers are required in close proximity to the RFID “tag” in order for it to be detected.